Metabolite Profiling of Guipi Pill Using UHPLC-Q-Orbitrap-HRMS and Determination of the Pharmacokinetics of its Major Prototype Components

Guipi Pill (GPP), a classic traditional formula used to treat anxiety disorders, demonstrates significant pharmacological activity. However, research on its pharmacodynamic material basis remains limited. UHPLC-Q-Orbitrap-HRMS was used to systematically analyze the metabolites of GPP in the blood, urine, bile, and feces of rats after oral administration and elucidate its in vivo metabolic processes. The pharmacokinetic characteristics of the major prototype components were determined using UHPLC-MS/MS. A total of 106 compounds (48 prototype components and 58 metabolites) were identified in GPP, which included the following six structural classes: phenylpropanoids, flavonoids and their glycosides, terpenoids and their glycosides, volatile oils, organic acids, and acetylenic glycosides. Nine of the metabolites were presumed to be novel compounds, which were previously unreported. Metabolic pathways involved Phase I reactions (hydrolysis, methylation, oxidation) and Phase II reactions (glucuronidation or sulfation of Phase I metabolites). Pharmacokinetic analysis revealed flavonoid glycosides (e.g., liquiritin) to exhibit a short time to attain maximum concentration (T_max), short elimination half-life (t_1/2), and short mean residence time (MRT), consistent with their structural features, whereas terpenoids (e.g., costunolide, atractylenolide I, dehydrocostus lactone, glycyrrhetinic acid) showed slow absorption, slow elimination, and a long MRT. The volatile oil, ligustilide, demonstrated rapid absorption and a long t_1/2. This study systematically delineates the metabolic characteristics and pharmacokinetic profiles of the major constituents of GPP in rats, providing a scientific basis for the further elucidation of its pharmacodynamic material basis and mechanisms of metabolic regulation.